Control device for internal combustion engine

Abstract

An internal combustion engine includes a water jacket, a cooling water pump as a cooling liquid pump, and an adjusting valve. A control device for the internal combustion engine executes the water stoppage control of increasing the temperature of the engine body by limiting the discharge of the cooling liquid from the water jacket by the adjusting valve, and an automatic stop and automatic startup control of automatically stopping and automatically starting the internal combustion engine. The control device increases the fuel injection amount for automatically starting the internal combustion engine in a case where the water stoppage control is being executed when the internal combustion engine is automatically stopped as compared with a case where the water stoppage control is not being executed when the internal combustion engine is automatically stopped.

The invention claimed is: 
     
       1. A control device for an internal combustion engine, the internal combustion engine including an engine body, a water jacket provided in the engine body and constituting a passage of cooling liquid for cooling the engine body, a cooling liquid pump, which supplies the cooling liquid to the water jacket, and an adjusting valve, which adjusts a flow rate of the cooling liquid discharged from the water jacket,
 wherein the control device is configured to execute 
 a water stoppage control for increasing a temperature of the engine body by limiting discharge of the cooling liquid from the water jacket by the adjusting valve, 
 an automatic stop and automatic startup control for automatically stopping the internal combustion engine when an automatic stop condition is satisfied, and for automatically starting the internal combustion engine when an automatic startup condition is satisfied, and 
 a control for increasing a fuel injection amount for automatically starting the internal combustion engine in a case where the water stoppage control is being executed when the internal combustion engine is automatically stopped as compared with a case where the water stoppage control is not being executed when the internal combustion engine is automatically stopped, under a condition that a cooling water temperature for calculating the fuel injection amount for the automatic startup in the case where the water stoppage control is being executed when the internal combustion engine is automatically stopped is the same as a cooling water temperature for calculating the fuel injection amount for the automatic startup in the case where the water stoppage control is not being executed when the internal combustion engine is automatically stopped. 
 
     
     
       2. The control device for an internal combustion engine according to  claim 1 , wherein the control device is configured to calculate a fuel injection amount for the automatic startup based on the cooling water temperature and elapsed time from the automatic stop, and
 the control device is configured to increase the fuel injection amount for the automatic startup in the case where the water stoppage control is being executed when the internal combustion engine is automatically stopped as compared to the case where the water stoppage control is not being executed when the internal combustion engine is automatically stopped under a condition that the elapsed time for calculating the fuel injection amount for the automatic startup in the case where the water stoppage control is being executed when the internal combustion engine is automatically stopped is the same as the elapsed time for calculating the fuel injection amount for the automatic startup in the case where the water stoppage control is not being executed when the internal combustion engine is automatically stopped. 
 
     
     
       3. The control device for an internal combustion engine according to  claim 2 , wherein the control device is configured such that a difference between the fuel injection amount for the automatic startup in the case where the water stoppage control is being executed when the internal combustion engine is automatically stopped and the fuel injection amount for the automatic startup in the case where the water stoppage control is not being executed when the internal combustion engine is automatically stopped is larger at a second predetermined period from an elapse of a first predetermined period to an elapse of a second predetermined time than at the first predetermined period from the automatic stop of the internal combustion engine to an elapse of the first predetermined time, under the condition that the cooling water temperature for calculating the fuel injection amount for the automatic startup in the case where the water stoppage control is being executed when the internal combustion engine is automatically stopped is the same as the cooling water temperature for calculating the fuel injection amount for the automatic startup in the case where the water stoppage control is not being executed when the internal combustion engine is automatically stopped and that the elapsed time for calculating the fuel injection amount for the automatic startup in the case where the water stoppage control is being executed when the internal combustion engine is automatically stopped is the same as the elapsed time for calculating the fuel injection amount for the automatic startup in the case where the water stoppage control is not being executed when the internal combustion engine is automatically stopped. 
     
     
       4. The control device for an internal combustion engine according to  claim 3 , wherein the control device is configured to make the difference when the elapsed time is long larger than the difference when the elapsed time is short at the second predetermined period. 
     
     
       5. The control device for an internal combustion engine according to  claim 3 , wherein the control device is configured to make the difference constant at a third predetermined period from an elapse of the second predetermined period to an elapse of a third predetermined time. 
     
     
       6. A control device for an internal combustion engine, the internal combustion engine including an engine body, a water jacket provided in the engine body and constituting a passage of cooling liquid for cooling the engine body, a cooling liquid pump, which supplies the cooling liquid to the water jacket, and an adjusting valve, which adjusts a flow rate of the cooling liquid discharged from the water jacket,
 wherein the control device includes circuitry configured to execute 
 a water stoppage control for increasing a temperature of the engine body by limiting discharge of the cooling liquid from the water jacket by the adjusting valve, 
 an automatic stop and automatic startup control for automatically stopping the internal combustion engine when an automatic stop condition is satisfied, and for automatically starting the internal combustion engine when an automatic startup condition is satisfied, and 
 a control for increasing a fuel injection amount for automatically starting the internal combustion engine in a case where the water stoppage control is being executed when the internal combustion engine is automatically stopped as compared with a case where the water stoppage control is not being executed when the internal combustion engine is automatically stopped, under a condition that a cooling water temperature for calculating the fuel injection amount for the automatic startup in the case where the water stoppage control is being executed when the internal combustion engine is automatically stopped is the same as a cooling water temperature for calculating the fuel injection amount for the automatic startup in the case where the water stoppage control is not being executed when the internal combustion engine is automatically stopped. 
 
     
     
       7. A method for controlling an internal combustion engine, the internal combustion engine including an engine body, a water jacket provided in the engine body and constituting a passage of cooling liquid for cooling the engine body, a cooling liquid pump, which supplies the cooling liquid to the water jacket, and an adjusting valve, which adjusts a flow rate of the cooling liquid discharged from the water jacket, the control method comprising:
 increasing a temperature of the engine body by limiting discharge of the cooling liquid from the water jacket by the adjusting valve; 
 automatically stopping the internal combustion engine when an automatic stop condition is satisfied, and automatically starting the internal combustion engine when an automatic startup condition is satisfied, and 
 increasing a fuel injection amount for automatically starting the internal combustion engine in a case where the water stoppage control is being executed when the internal combustion engine is automatically stopped as compared with a case where the water stoppage control is not being executed when the internal combustion engine is automatically stopped, under a condition that a cooling water temperature for calculating the fuel injection amount for the automatic startup in the case where the water stoppage control is being executed when the internal combustion engine is automatically stopped is the same as a cooling water temperature for calculating the fuel injection amount for the automatic startup in the case where the water stoppage control is not being executed when the internal combustion engine is automatically stopped.